enable nvfuser matmul

thunder/tests/test_nvfuser.py

@@ -850,3 +850,26 @@ def get_num_fusions(cfn):
     assert get_num_fusions(cfn_without_fusion) == 0
 
     nvfuserex.set_fuel(thunder.extend.FUEL_LEVEL.UNLIMITED)
+
+
+@instantiate(dtypes=(thunder.float16, thunder.bfloat16), devicetypes=(devices.DeviceType.CUDA,), executors=(nvFuserExecutor,))
+def test_matmul(executor, device: str, dtype: dtypes.dtype):
+    m, n, k = 128, 64, 32
+    torch_dtype = ltorch.to_torch_dtype(dtype)
+    a = torch.randn((m, k), dtype=torch_dtype, device=device)
+    b = torch.randn((k, n), dtype=torch_dtype, device=device)
+
+    def fn(a , b):
+        return a.matmul(b);
+
+    compiled_func = thunder.compile(
+        fn,
+        executors_list=executor.executors_list(),
+        nv_enable_matmul=True,
+    )
+    out = compiled_func(a, b)
+
+    traces = thunder.last_traces(compiled_func)
+    fusions = examine.get_fusions(traces[-1])
+    assert len(fusions) == 1
+    assert torch.allclose(out, torch.matmul(a, b))